Mold



2,177,04&

J. WIRTZ Oct. 24, 1939.

MOLD

Filed NOV. 2, 1938 Jjkn Maia,

Patented Oct. 24, 1939 UNITED STATES PATENT OFFiCE MOLD John Wirtz, PortHuron, Mich.

Application November 2, 1938, Serial No. 238,466

the body of the mold member from the face thereof extending therethroughto a depth sufiicient 2 Claims.

This invention relates to an improved construction of mold for castingstorage battery grids and similar devices. An object of the invention isto provide a mold of this type in which the air in the mold and thegases created during the pouring of the molten metal into the mold arepermitted to escape by means of novel vent openings of such characterthat they will not become plugged or clogged with molten metal duringthe pouring operation.

In the molds of this type heretofore used, difficulty has beenencountered because of the plugging which occurred in the vents. Thevent holes occurring in the mold throughout the grid-forming portion areformed of large holes of uniform diameter which are formed in the backof the mold to meet a smaller hole of uniform diameter drilled from theface of the mold. It has been found that there is a tendency for themolten metal to clog or plug these holes, and the pouring operation hadto be stopped until these vent holes were cleaned out either by meltingor drilling out the lead or other material which settled therein.

One of the objects of this invention, therefore, is to provide a meansfor overcoming this difficulty. v

For a more complete understanding of the invention, reference is made tothe accompanying drawing in which one embodiment of the invention isillustrated. Throughout the description, like reference characters referto like parts in the drawing.

In the drawing:

Figure 1 shows an end, partly diagrammatic view of my improved mold;

Figure 2 shows an elevation of the mold face of one of the partsthereof;

Figure 3 shows an enlarged detail of a portion of the face of the moldshown in Figure 2; and

Figure 4 shows an enlarged sectional detail of a portion of the moldface shown along the line 4-4 in Figure 3.

My mold comprises a pair of separable sections I and 2, each of which isprovided with a back 3 and a face 4. For the purpose of venting thegases which occur during the pouring operation, a series of ventopenings 5 are provided over the areaof the back of the mold. Theseopenings are formed when the mold is cast, or by drilling or otherwiseproducing a hole which extends from the back of the mold substantiallythrough the entire body 2 thereof, terminating just short of the face 4thereof. To meet each of these vent openings, a series of holes 6 areformed in to reach the vent openings 5.

These holes 5 are substantially smaller in diameter than the hole 5 andare preferably arranged four in number symmetrically around the axis ofthe vent hole 5.

Each of these openings 5 is tapered as at I, from the base of theopening 5 in the direction of the face 4 of the mold.

In practice it has been found satisfactory to form the back vent opening5 about %4" in diameter, and to form shown.

These dimensions are not to be considered as limitations and may bevaried, but they are set forth simply for the purpose of disclosing onepractical embodiment of the invention. With these dimensions, it hasbeen found that four small vent openings 6 can be supplied to feed eachlarger vent opening 5.

By the use of this structure, it has been found that the vents 6 do notbecome clogged or plugged with molten metal during the pouringoperation, since if any metal enters these openings, it quickly dropsthrough into the large opening 5 because the tapered walls I of the vent6 prevent the material from adhering thereto.

Having thus described my invention, I claim:

1. A vented mold in which the vents are substantially self-freeing ofthe molding material which may pass therethrough, said mold havingcooperating wall sections to form a molded article therebetween, eachvent comprising a large opening extending from the back through a wallof said mold and .terminating short of the face thereof to provide amaterially reduced wall portion at said face adjacent said opening, saidreduced portion having a short tapered opening extending therethrough,the restricted part of said tapered opening occurring at the face of themold, the taper of said opening being of a degree sufficient to preventadhesion to said tapered wall of such molding material as may enter saidvent,

thereby eliminating the stoppage of the vent opening.

JOHN WIRTZ.

